Various abbreviations that appear in the specification and/or in the drawing figures are defined as follows:
3G third generation mobile phone network
EAP-TLS extensible authentication protocol-TLS
EAP-TTLS: extensible authentication protocol-TTLS
GNU/Linux system having a Linux kernel and GNU (GNU's Not Unix) software
GSM global system for mobile communications
IMSI international mobile subscriber identity
MAC address media access control address (the link-layer device address)
PKMv2 privacy and key management protocol version 2 (IEEE 802.16e-2005)
SIM subscriber identity module
TLS transport layer security
TTLS tunneled transport layer security
WiFi wireless fidelity
WiMAX world interoperability for microwave access (IEEE 802.16e network)
WLAN wireless local access network
X.509 X.509 certificate
The following publications may be of interest to the ensuing description, and each are incorporated by reference in their entirety:    The TLS Protocol, Version 1.0, T. Dierks, C. Allen, January 1999, RFC 2246;    PPP EAP TLS Authentication Protocol, B. Aboba, D. Simon, October 1999, RFC 2716;    EAP Tunneled TLS Authentication Protocol (EAP-TTLS), P. Funk, S. B. Wilson, February 2002, IETF PPPEXT Working Group, Internet Draft RFC; and    Internet X.509 Public Key Infrastructure Certificate and CRL Profile, R. Housley, W. Ford, W. Polk, D. Solo, January 1999, RFC 2459.
WiMAX network operators may have an interest in subsidy locking devices to their mobile WiMAX networks. Since it can be expected that mobile devices will be commodity items purchased from retail consumer electronics stores, it can be anticipated that locking and unlocking the mobile devices will be accomplished over-the-air (i.e., not at a dealer and/or operator location). WiMAX, as a protocol, does not specifically support subsidy locking, and further there may be no removable SIM card to facilitate a subsidy locking operation. As a result, if subsidy locking is to be achieved then it must be implemented utilizing inherent properties of the WiMAX network.
Further, at least one type of WiMAX mobile device known to the inventors is expected to rely on an open GNU/Linux-based platform to enable Internet access. In this case no non-hackable security services can be implemented in the kernel or user space.
In GSM and 3G phones a subsidy lock feature is known as a “SIM lock”, where the IMSI of the SIM card defines a specific operator. The GSM or 3G phone can be factory programmed to reject any other SIM cards than those having a specific IMSI numbering block. Such phones that are SIM-locked before sale can be unlocked by entering a code provided by the specific operator.